Various N-acyl substituted 3-deoxydihydromorphines were prepared to investigate their fungal and microbial transformation. Insolubility in commonly used solvent for such biotransformation added unexpected difficulties to this project. This investigation is being continued with 3-deoxydihydronormorphine and N-ethoxyacetyl-3-deoxydihydronormorphine, which both were soluble in aqueous systems.